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Appendix VI.

link motion being decided upon, strips of cardboard are provided
to represent the rods and the link separately, and the actual
positions of the link are set out as the cranks revolve. Properly
treated, this method can be made even more accurate than a
model, and a sample of the work has been given in Fig. ion as a
notion of the process.

Pp. 650 and 773. The Whitehead Governor, Fig. 1012,
is a most successful high-speed governor. Like the Proell
governor, p. 659, p. 657, the balls move out horizontally,
eliminating one resistance, that of gravity. This alone would

make the governor over-sensitive and cause it to * hunt,' but for
the intervention of a dashpot and springs. The weights D D and
arms EE form adjustable bell-crank levers that press upon the
dashpot j when the balls fly out, with increased speed. The
piston of the dashpot meanwhile remains all but stationary, being
supported by the spring K in the upper chamber. The tendency
of the dashpot is to move the piston downward by pressure on spring
L, and this is resisted partly by the spring K and partly by the